In prehistoric times people worried of the sun’s absence and performed elaborate rituals to encourage it back. In Roman times the celebration of Saturnalia happened on December 25th, the date of the solstice in the Julian calendar, later adopted by the early Christian church as the alleged (but improbable) date for the birth of Jesus, leading to the celebration of Christmas. And because other celebrations such as Hannukah and Kwanzaa arguably arose from the large-scale popularity of Christmas, we can thank the ongoing influence of the Winter Solstice for the host of celebrations taking place as the year comes to an end.